The bicycle is a marvelous invention, supporting loads many times its own weight over all types of surfaces and terrain, yet powered by man, mostly without undue stress to the human body. According to Encyclopaedia Britannica, the earliest bicycle was invented in Scotland, about 1839, by Kirkpatrick MacMillan and improved a few years later by Gavin Dalzell. The modern bicycle, known also as the "safety bicycle", was invented by H. J. Lawson in 1876 and was first marketed in a useful form in 1885. One of the features of the modern bicycle is a chain or indirect drive, transferring power from pedals driving a crank below and forward of the saddle to a rear gear and axle associated with the rear wheel. Thus, bicycle design has basically remained the same for over 100 years, with improvements in materials, gearing, brakes and manufacturing methods. On the other hand, earlier bicycles, prior to the modern bicycle, frequently employed direct drive, i.e. direct transfer of power to a wheel without use of a chain or belt.
Both early and modern bicycles have relatively high centers of gravity because a rider is seated generally upright. The invention of the recumbent cycle lowers the center of gravity, but this is an exception. See, for example, U.S. Pat. No. 5,280,936 to D. Schmidlin or U.S. Pat. No. 5,242,181 to H. Fales et al.
In U.S. Pat. No. 5,156,412, O. Meguerditchian teaches a bidirectional rectilinear motion system for pedals of a bicycle whereby linear motion is converted to rotary motion for driving a chain and a rear wheel. The linear motion saves energy which is otherwise lost in providing circular motion to a crank. In U.S. Pat. No. 555,242 to J. Hannenbeck, a cycle is shown having pinions on the rear axle which are driven by reciprocating pedals, connected to jointed arms having toothed sectors at the rearward ends for traveling around the pinions. U.S. Pat. No. 3,998,469 to F. Ruiz teaches a similar drive mechanism.
Notwithstanding advances of the prior art, there is a need for a more efficient bicycle which maximizes human power, while minimizing energy losses. An object of the invention was to provide such a bicycle.